Transistor implemented heat source

ABSTRACT

A heat source comprised of one or more transistors or transistor packages mechanically connected to a heat plate. The heat generation is accomplished by the direct and precisely controlled heat generated by one or more transistors through the precise duty cycle control of a high-frequency Pulse-Width-Modulated (PWM) which is generated based on the sensed temperature and current generated by one or more of the transistor(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional patent applicationSer. No. 62/305,172 titled “Transistor Implemented Heat Source”, filedon Mar. 8, 2016 the disclosure of which is herein incorporated byreference in its entirety.

PATENTS CITED

The following documents and references are incorporated by reference intheir entirety, Rich (U.S. Pat. No. 3,002,802), Del Duca (U.S. Pat. No.3,330,941), Schwarz et al (U.S. Pat. No. 4,041,276), Dietz et all (U.S.Pat. No. 5,517,053), Eppes et al (U.S. Pat. No. 6,878,172), Zhou et al(U.S. Pat. No. 7,952,599), Goldin et al (U.S. Pat. No. 8,548,312),Santuorvo et al (U.S. Pat. No. 9,012,810), Bashir et al ((U.S. Pat. No.9,433,943) and REC Johnson et al, EDN Network Use a transistor as aheater, April 2012.

FIELD OF THE INVENTION

The present invention relates to a system and method for generating heatin an efficient fashion, and particularly to the use of transistors as aprimary heat source.

DESCRIPTION OF THE RELATED ART

Since their invention, transistors have been used by engineersinterested in controlling a current over a load. With time, once flimsyand delicate components have matured into reliable and robust currentdrivers capable of amplifying signals and providing designers withmyriad other control options.

In fact, in many cases, cooling the transistor has resulted intransistor packages with significant heat dissipation packages, thecontroller has become a contributor to the heat equation.

What is needed, is to use the transistor package not just as acontroller for a heater, but as the actual heating unit itself.

SUMMARY OF THE INVENTION

This section is for the purpose of summarizing some aspects of thepresent invention and to briefly introduce some preferred embodiments.Simplifications or omissions may be made to avoid obscuring the purposeof the section. Such simplifications or omissions are not intended tolimit the scope of the present invention.

In one aspect the invention is about a heat generating apparatuscomprising an electronic circuit comprised of an electronic calculatingcomponent, a circuit driver component, a temperature measurementcomponent, a current measurement component and one or more transistorsand wherein said electronic calculating component is capable ofinterfacing with said temperature measurement and said currentmeasurement components to generate a transistor control signal throughsaid circuit driver component. In another aspect, said temperaturemeasuring component is comprised of two or more resistors, said currentmeasurement component is comprised of a hall effect sensor, said circuitdriver component is comprised of an IC driver and one or more resistors,said electronic calculating component is comprised of one of; CPU, FPGAand/or ASIC, and said transistor control signal is comprised of aPulse-Width-Modulation (PWM) signal. In yet another aspect, said circuitdriver component IC has a bandwidth over 10 KHz. In another aspect, saidone or more transistors are mechanically coupled to a heat transmittingcomponent.

In another aspect, the invention is about a method for generating heatwithout external resistors, said method comprising the steps ofproviding an electronic circuit comprised of an electronic calculatingcomponent, a circuit driver, a temperature measurement component, acurrent measurement component and one or more transistors and whereinsaid electronic calculating component is capable of interfacing withsaid temperature measurement and said current measurement components togenerate a transistor control signal through said circuit driver. Inanother aspect, said temperature measuring component is comprised of twoor more resistors, said current measurement component is comprised of ahall effect sensor, said circuit driver component is comprised of an ICdriver and one or more resistors, said electronic calculating componentis comprised of one of; CPU, FPGA and/or ASIC, and said transistorcontrol signal is comprised of a Pulse-Width-Modulation (PWM) signal. Inyet another aspect, said circuit driver component IC has a bandwidthover 10 KHz. In another aspect, said one or more transistors aremechanically coupled to a heat transmitting component.

Other features and advantages of the present invention will becomeapparent upon examining the following detailed description of anembodiment thereof, taken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an illustration of a proposed system block diagram,according to an exemplary embodiment of the invention.

FIG. 2 shows an illustration of a system pin-out and wiring diagram,according to an exemplary embodiment of the invention.

FIG. 3 shows a top view illustration of the system embodiment as aheating component, according to an exemplary embodiment of theinvention.

FIG. 4 shows a side view illustration of the system embodiment as aheating component, according to an exemplary embodiment of theinvention.

The above-described and other features will be appreciated andunderstood by those skilled in the art from the following detaileddescription, drawings, and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This section is for the purpose of summarizing some aspects of thepresent invention and to briefly introduce some preferred embodiments.Simplifications or omissions may be made to avoid obscuring the purposeof the section. Such simplifications or omissions are not intended tolimit the scope of the present invention.

To provide an overall understanding of the invention, certainillustrative embodiments and examples will now be described. However, itwill be understood by one of ordinary skill in the art that the same orequivalent functions and sequences may be accomplished by differentembodiments that are also intended to be encompassed within the spiritand scope of the disclosure. The compositions, apparatuses, systemsand/or methods described herein may be adapted and modified as isappropriate for the application being addressed and that those describedherein may be employed in other suitable applications, and that suchother additions and modifications will not depart from the scope hereof.

Simplifications or omissions may be made to avoid obscuring the purposeof the section. Such simplifications or omissions are not intended tolimit the scope of the present invention. All references, including anypatents or patent applications cited in this specification are herebyincorporated by reference. No admission is made that any referenceconstitutes prior art. The discussion of the references states whattheir authors assert, and the applicants reserve the right to challengethe accuracy and pertinence of the cited documents. It will be clearlyunderstood that, although a number of prior art publications arereferred to herein, this reference does not constitute an admission thatany of these documents form part of the common general knowledge in theart.

As used in the specification and claims, the singular forms “a”, “an”and “the” include plural references unless the context clearly dictatesotherwise. For example, the term “a transaction” may include a pluralityof transaction unless the context clearly dictates otherwise. As used inthe specification and claims, singular names or types referenced includevariations within the family of said name unless the context clearlydictates otherwise.

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “lower,” “upper,” “bottom,” “top,”“front,” “back,” “left,” “right” and “sides” designate directions in thedrawings to which reference is made, but are not limiting with respectto the orientation in which the modules or any assembly of them may beused.

It is acknowledged that the term ‘comprise’ may, under varyingjurisdictions, be attributed with either an exclusive or an inclusivemeaning. For the purpose of this specification, and unless otherwisenoted, the term ‘comprise’ shall have an inclusive meaning—i.e. that itwill be taken to mean an inclusion of not only the listed components itdirectly references, but also other non-specified components orelements. This rationale will also be used when the term ‘comprised’ or‘comprising’ is used in relation to one or more steps in a method orprocess.

Referring to FIGS. 1 and 2 we see a proposed system block diagram 100,and exemplary schematic 200 which shows the energy source 102, which maybe comprised of an AC/DC voltage converter, a battery or capacitorsource or any suitable DC source. Said source 102 is connected to aprocessing component 106 (a Central Processing Unit (CPU), FieldProgrammable Gate Array (FPGA), Application specific IC (ASIC) orsimilar unit capable of comparing current sensing components 110 andtemperature sensing components 112 and using these to drive a circuitdriver 108 in combination with a Duty Cycle generator/work periodmonitor 114 connected to one or more transistors circuits 104 whichgenerate heat without any separate resistor components generating anysizeable heat component.

In one embodiment 200, the processing component unit 106 is a CPU (suchas the Atmel ATMEGA328-MU) which controls the process through thegeneration of a high-frequency Pulse-Width-Modulator (PWM) signalthrough its pin 27. The PWM goes across the R2 resistor 204, into theDriver 108 component (such as an Infineon IR4427 or similar part). ThePWM signal is derived from a Proportional-Derivative-Integrated (PDI)equation that is proportional to the signals sensed at the temperaturesensing component 112 and the current sensing component 110. In oneembodiment, the current is sensed using a SHUNT resistor. In analternate embodiment, a Hall Effect sensor is used (using a componentsuch as the Allegro ACS712 or similar). The current being sensed is thatcoming out of the transistors Q1-Q5, described below. The temperaturebeing sensed, is that of the heat plate 302.

Based on the calculated PID signal, the PWM signal at pin 27 drives thedriver 108 output element with a PWM signal (212 to 214) supplied to theone or more transistors Q1-Q5 (202, 216, 218, 220, 222) acting as thesole direct heating elements (any other heat generated by the resistiveand other Integrated Circuit components in the system being ancillary).This is critical, in effect and unlike other references, the output ofQ1-Q5 is not driving a resistor that heats up, but directly acting asthe heating element. Note that the shown schematic 200 is optimal forcontrolling one to five transistors, but may be replicated as requiredwithin a heating system.

The CPU 106 performs a Proportional-Integrative-Derivative (PID) controlloop to ensure the PWM signal allows the current going through the oneor more Q transistors (202, 216, 218, 220, 222) reaches the desiredtemperature without compromising the structural integrity of the Qphysical package (and the control is of course is based on the knowncharacteristics of the Q transistor).

In effect, the high frequency PWM signal forces the one or moretransistors Q1-Q5 to alternate between a no load/high load condition. Inthe high load condition their current output is almost zero, while inthe no-load condition, their current output is maximized. This largecurrent (a function of the physical construction of the transistor)generates a large amount of heat directly on the transistor package. ThePWM duty cycle alternates the one or more transistors go between a zeroresistance load and an infinite resistance load, with the zeroresistance being of necessity a brief period. This action results inbrief overheating, followed by cooling of the one or more Q package. Asnoted, a single CPU 106 could control one or more Q heating sources. Thevarious resistors in the circuit, are a function of how manyheat-generating transistors Q are desired, not selected for their heatgenerating capacity.

One embodiment of the heating plate 104 may be that of a heating iron,or a heating plate for an air drier. In one exemplary embodiment, such asystem (top view) 300, shows one or more transistor packages 302, 304,306, 308, 310 whose heat sinks are thermally attached to a plate 302.The side view 400 shows these 304, 310 over the plate 302. Note thetransistors may be already packaged (such as the IXYS IXFH6N100 orsimilar) which is mechanically/chemically connected to a heat sink,thermal conductive surface or plate 302, and/or be individual directtransistors similarly bonded to the plate 302.

In operation, the system will take energy from a power source,temperature and thermal goal instructions (from one or more devicesand/or memory), proceed to calculate the desired temperature, thepresent temperature (from the sensor 112), the present current (110),and then calculate (based on the control desired, i.e. linear, PWM, PID,etc.) the rate of heating (e.g. a degree per second, etc.) based on theheating transistors 302, 304, 306, 308, 310 and the heat plate 104characteristics.

The system then proceeds to drive the current on the CPU 106, whichdrives the driver 108 (through the transistor), in turn driving the oneor more heating transistors Q1 302, 304, 306, 308, 310. Once the heat isgenerated by the transistors (reflecting on the temp. sensor 112), thesystem proceeds to monitor the current sensor 110 (to ensure against anyfailures of short circuits), resulting in the system operation. Thecurrent controlled by the one or more Q1 transistors 302, 304, 306, 308,310, may then be fed back to the energy source, resulting in significantenergy savings.

In operation, the CPU 106 receives a desired temperature goal (includingfactors such as the desired temperature, rate of heating, total energyto be used (hourly/total)). Such data may be preprogrammed, availablefrom memory, and/or one or more user interface. Such an I/F may beaccomplished by a programmable switch or knob, as well as by anapplication running on a separate device (say the User's computer,tablet or Smartphone) either via wired or wireless means (such asBluetooth, Wi-Fi, etc).

In addition to the desired temperature and/or usage parameters (asdefined above), the CPU may also receive the material and othercharacteristics about the material being heated. This may include, as anexample, that the item being laundered be is silk, but mounted on aplastic backing, so that the iron may know to provide significant heat,and to also overcompensate, under compensate and/or be similarlyadjusted based on the thermal characteristics of the item.

As shown, the system 200 that has five heat generating transistors Q1-Q5(202, 902, 904, 906, 908), which may be a part like the IFXH6N100, whichare controlled through a PWM signal derived from the measure platetemperature 112 and the transistor short circuit current measurement 110(a hall effect current sensor), both measurements go into an A/D 8 bitconverter (although it may be any number of bits), the temperature goinginto pin(s) 4-6, 8, 9 and the current going into pin 7. As noted, theshort circuit of the one or more transistors Q1-Q5 must be very brief,to prevent the part from overheating and/or burning out. As such,applicant has found that the driver 108 must be capable of fastswitching. In practice, much faster in transition than 3 KHz, andpreferably above 10 KHz transition from on to off.

In operation, the current and temperature signals are measured as 8 bitsignals in order to generate a Pulse-Width-Modulation (PWM) controlsignal. This may be accomplished through a CPU, FPGA, ASIC or any othersuitable software and/or hardware implementation. The temperature 112signal is digitized into a digital signal, the current is monitored 110and also similarly digitized. Both are monitored to ensure the setpoints(user/electrical code or otherwise determined) are not exceeded. Onceboth temperature and current are measured, the PWM is calculated usingthe following;

-   -   FUNCTION(FIRST ARGUMENT (PWM OUTPUT PIN 204), SECOND ARGUMENT        (ENSURE PWM VALUE DOES NOT EXCEED SET POINT 112, 110).

Thus, the output of the PWM comes to be a PWM output signal 204 whichmay be on/off with a duty cycle signal that may be on from zero to 100%of the cycle. In one example, we have found that the PWM is on only 17%of the time (at a maximum), and may be as low as 5% (with the signalbeing 0 the rest of the time) as each transistor heats in its mostefficient fashion. In one embodiment, we find that the PWM signal 210must be switched at high frequency (preferably at 10 KHz to 30 KHzrange), so that the latency in the transistor does not cause a partfailure within the Q1-Q5 transistor. In one embodiment, the 8 bit signalgenerated results in a 0 bit (0 volts) and a 255 bit being 12 volts.

In an alternate embodiment of this, the unit is equipped with an inputplug and an output plug. So when a user desires to re-circulate thepower to the outlet circuit, they simply plug both and the energy entersthe system through one and returns to the system through another or viceversa.

CONCLUSION

In concluding the detailed description, it should be noted that it wouldbe obvious to those skilled in the art that many variations andmodifications can be made to the preferred embodiment withoutsubstantially departing from the principles of the present invention.Also, such variations and modifications are intended to be includedherein within the scope of the present invention as set forth in theappended claims. Further, in the claims hereafter, the structures,materials, acts and equivalents of all means or step-plus functionelements are intended to include any structure, materials or acts forperforming their cited functions.

It should be emphasized that the above-described embodiments of thepresent invention, particularly any “preferred embodiments” are merelypossible examples of the implementations, merely set forth for a clearunderstanding of the principles of the invention. Any variations andmodifications may be made to the above-described embodiments of theinvention without departing substantially from the spirit of theprinciples of the invention. All such modifications and variations areintended to be included herein within the scope of the disclosure andpresent invention and protected by the following claims.

The present invention has been described in sufficient detail with acertain degree of particularity. The utilities thereof are appreciatedby those skilled in the art. It is understood to those skilled in theart that the present disclosure of embodiments has been made by way ofexamples only and that numerous changes in the arrangement andcombination of parts may be resorted without departing from the spiritand scope of the invention as claimed. Accordingly, the scope of thepresent invention is defined by the appended claims rather than theforegoing description of embodiments.

The invention claimed is:
 1. A high voltage and high heat generatingapparatus comprising: an electronic circuit comprised of an electroniccalculating component, a circuit driver component, a temperaturemeasurement component, a current measurement component and one or moretransistors, wherein one or more of said transistors is comprised of ametal oxide field effect transistor with silicon carbide technology;wherein said electronic calculating component is capable of interfacingwith said temperature measurement and said current measurementcomponents to generate a transistor control signal through said circuitdriver component; wherein said temperature measuring component iscomprised of two or more resistors, with one of them being said at leastone transistor's internal resistor which is used as the circuit's loadresistance; said current measurement component is comprised exclusivelyof a hall effect sensor; said circuit driver component is comprised ofan IC driver and one or more resistors; said electronic calculatingcomponent is comprised of one of; CPU, FPGA and/or ASIC; and saidtransistor control signal is comprised of a Pulse-Width-Modulation (PWM)signal implementing proportional-integral-derivative (PID) control. 2.The heat generating apparatus of claim 1 wherein; said circuit drivercomponent IC has a bandwidth over 10 KHz.
 3. The heat generatingapparatus of claim 2 wherein; said one or more transistors aremechanically coupled to a heat transmitting component.
 4. The heatgenerating apparatus of claim 1 wherein; said one or more transistorsare mechanically coupled to a heat transmitting component.
 5. A methodfor generating heat without external resistors, said method comprisingthe steps of: providing an electronic circuit comprised of an electroniccalculating component, a circuit driver, a temperature measurementcomponent, a current measurement component and one or more transistors,wherein one or more of said transistors is comprised of a metal oxidefield effect transistor with silicon carbide technology; wherein saidelectronic calculating component is capable of interfacing with saidtemperature measurement and said current measurement components togenerate a transistor control signal through said circuit driver whereinsaid temperature measuring component is comprised of two or moreresistors, with one of them being said at least one transistor'sinternal resistor which is used as the circuit's load resistance; saidcurrent measurement component is comprised exclusively of a hall effectsensor; said circuit driver component is comprised of an IC driver andone or more resistors; said electronic calculating component iscomprised of one of; CPU, FPGA and/or ASIC; and said transistor controlsignal is comprised of a Pulse-Width-Modulation (PWM) signalimplementing proportional-integral-derivative (PID) control.
 6. The heatgenerating method of claim 5 wherein; said circuit driver component IChas a bandwidth over 10 KHz.
 7. The heat generating method of claim 6wherein; said one or more transistors are mechanically coupled to a heattransmitting component.
 8. The heat generating method of claim 5wherein; said one or more transistors are mechanically coupled to a heattransmitting component.